1. Field of the Invention:
This invention relates generally to insulating electrical devices, and, more particularly, to terminal bushings for transformers.
2. Description of the Prior Art:
Secondary bushings for use on outdoor transformers have customarily consisted of porcelain and a metal conductor which are locked together mechanically and sealed with gaskets. The sealing requirement has added considerably to the cost of the bushing. Various attempts have been made to achieve a more economical product without sacrificing a suitable operating bushing. For example, replacement of the porcelain member with an epoxy resin cast around the conductor proved unsatisfactory, because a required compromise in the resin composition to achieve a coefficient of expansion comparable to that of the conductor resulted in a reduction of the arc and track resistance. U.S. Pat. No. 3,433,893 generally discloses an electrical bushing of the type involved herein.